An Introduction to the Population Ecology Approach

For a very long time, the essential traits of populations of organized interests — their density and diversity — were not considered to be especially interesting. Rather, they were assumed to be simple tallies resulting from mobilization events whereby institutions became active in lobbying or they, along with individual citizens, joined groups or associations that lobbied (Truman 1951; Olson 1965). This changed with the publication of Gray and Lowery’s The Population Ecology of Interest Representation in 1996 (also see: Lowery and Gray 1995). Inspired by core theories of population biology and organization ecology, they outlined a theory that both accounted for observed variations in the density and diversity of interest communities in the American states and suggested ways in which these emergent population characteristics shape organization survival and adaptation, the strategies and tactics interest organizations employ, and how influential these can be in political contexts. Since 1996, the organization ecology research program has engendered work on all of these topics and has been applied to a wide range of political systems, including the European Union, its member states, and international organizations. In short, we now know that the structure of interest communities matters a great deal.